Imported from OCIOStateOfNebraska/stateofnebraska-aem (
.agents/skills/aem-replication/replication-api/SKILL.md). Install upstream withnpx skills add OCIOStateOfNebraska/stateofnebraska-aem --skill replication-api. Copyright stays with the author (Apache-2.0).
AEM 6.5 LTS Replication API
This skill provides comprehensive guidance on using the official Adobe Experience Manager 6.5 LTS Replication API for programmatic replication operations. The API enables custom code to activate, deactivate, and manage content distribution workflows.
When to Use This Skill
Use this skill when you need to:
- Programmatically activate/deactivate content from custom code
- Build custom replication workflows in OSGi services or servlets
- Integrate replication with external systems
- Implement custom replication triggers and automation
- Check replication status in application logic
- Create custom content distribution tools
- Bulk replicate content via scripts
- Implement conditional replication logic
Prerequisites
- AEM 6.5 LTS environment with configured replication agents
- Java development environment for AEM
- Maven project with AEM dependencies
- Understanding of OSGi services and Sling ResourceResolver
- Configured replication agents (see
configure-replication-agentskill) - Service user or user session with replication permissions
Official API Documentation
All public replication APIs are documented in the official Adobe AEM 6.5 LTS JavaDoc:
- Package Summary (Complete API Reference): https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/package-summary.html
- Replicator Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/Replicator.html
- AgentManager Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/AgentManager.html
- ReplicationQueue Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/ReplicationQueue.html
- ReplicationListener Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/ReplicationListener.html
- AgentFilter Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/AgentFilter.html
- Agent Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/Agent.html
- ReplicationAction Class: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/ReplicationAction.html
- ReplicationOptions Class: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/ReplicationOptions.html
- ReplicationStatus Interface: https://developer.adobe.com/experience-manager/reference-materials/6-5-lts/javadoc/com/day/cq/replication/ReplicationStatus.html
Core API Components
1. Replicator Interface
The primary service for managing replication operations.
Service Type: OSGi Service
Package: com.day.cq.replication
Interface: com.day.cq.replication.Replicator
2. ReplicationActionType Enum
Defines the type of replication operation:
| Type | Purpose | Effect |
|---|---|---|
ACTIVATE |
Publish content | Sends to Publish instances |
DEACTIVATE |
Unpublish content | Removes from Publish |
DELETE |
Delete from Publish | Permanent removal |
TEST |
Test replication | Verifies connectivity |
REVERSE |
Reverse replicate | Publish → Author |
INTERNAL_POLL |
Internal polling | System use |
3. ReplicationOptions Class
Encapsulates optional parameters for replication requests.
4. ReplicationStatus Interface
Provides status information about replicated content.
Maven Dependencies
The Replication API is provided by the AEM uber-jar. Add to your pom.xml:
<dependency>
<groupId>com.adobe.aem</groupId>
<artifactId>uber-jar</artifactId>
<classifier>apis</classifier>
<scope>provided</scope>
</dependency>
The uber-jar version should match your AEM 6.5 LTS installation. The Replication API (com.day.cq.replication.*) is included in the uber-jar and available at runtime.
Replicator Interface Methods
Method 1: replicate(Session, ReplicationActionType, String)
Signature:
void replicate(Session session,
ReplicationActionType type,
String path)
throws ReplicationException
Parameters:
session- JCR session (user permissions determine access)type- ReplicationActionType (ACTIVATE, DEACTIVATE, DELETE, etc.)path- Content path to replicate (e.g., "/content/mysite/en/page")
Throws: ReplicationException if replication fails
Description: Triggers replication for a single path with default options.
Example:
import com.day.cq.replication.Replicator;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import org.apache.sling.api.resource.ResourceResolver;
import org.osgi.service.component.annotations.Reference;
import javax.jcr.Session;
@Reference
private Replicator replicator;
public void activatePage(ResourceResolver resolver, String pagePath)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath);
}
Method 2: replicate(Session, ReplicationActionType, String, ReplicationOptions)
Signature:
void replicate(Session session,
ReplicationActionType type,
String path,
ReplicationOptions options)
throws ReplicationException
Parameters:
session- JCR sessiontype- ReplicationActionTypepath- Content pathoptions- ReplicationOptions for custom configuration
Description: Initiates replication with customizable options for one path.
Example:
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.ReplicationOptions;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
public void activatePageSync(ResourceResolver resolver, String pagePath)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true); // Wait for completion
opts.setSuppressVersions(true); // Don't create versions
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath, opts);
}
Method 3: replicate(Session, ReplicationActionType, String[], ReplicationOptions)
Signature:
void replicate(Session session,
ReplicationActionType type,
String[] paths,
ReplicationOptions options)
throws ReplicationException
Parameters:
session- JCR sessiontype- ReplicationActionTypepaths- Array of content paths (String[])options- ReplicationOptions
Description: Handles replication across multiple paths with supplied settings.
Example:
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.ReplicationOptions;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
public void activateMultiplePages(ResourceResolver resolver, String[] pagePaths)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(false); // Async for better performance
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePaths, opts);
}
Method 4: checkPermission(Session, ReplicationActionType, String)
Signature:
void checkPermission(Session session,
ReplicationActionType type,
String path)
throws ReplicationException
Parameters:
session- JCR sessiontype- ReplicationActionTypepath- Content path
Throws: ReplicationException if user lacks permissions
Description: Verifies whether a user has sufficient permissions for replication activities.
Example:
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
public boolean canUserActivate(ResourceResolver resolver, String pagePath) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
try {
replicator.checkPermission(session, ReplicationActionType.ACTIVATE, pagePath);
return true; // User has permission
} catch (ReplicationException e) {
return false; // User lacks permission
}
}
Method 5: getReplicationStatus(Session, String)
Signature:
ReplicationStatus getReplicationStatus(Session session, String path)
Parameters:
session- JCR sessionpath- Content path
Returns: ReplicationStatus object or null if unavailable
Description: Retrieves the replication status for a given path.
Example:
import com.day.cq.replication.ReplicationStatus;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
import java.util.Calendar;
public ReplicationInfo getPageReplicationInfo(ResourceResolver resolver, String pagePath) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationStatus status = replicator.getReplicationStatus(session, pagePath);
if (status != null) {
boolean isActivated = status.isActivated();
Calendar lastPublished = status.getLastPublished();
String lastPublishedBy = status.getLastPublishedBy();
return new ReplicationInfo(isActivated, lastPublished, lastPublishedBy);
}
return null;
}
Method 6: getActivatedPaths(Session, String)
Signature:
Iterator<String> getActivatedPaths(Session session, String path)
throws ReplicationException
Parameters:
session- JCR sessionpath- Root path for subtree
Returns: Iterator of activated paths
Throws: ReplicationException
Description: Returns paths of all activated nodes for the given subtree path.
Example:
import com.day.cq.replication.ReplicationException;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public List<String> getActivatedPages(ResourceResolver resolver, String rootPath)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
Iterator<String> activatedPaths = replicator.getActivatedPaths(session, rootPath);
List<String> result = new ArrayList<>();
while (activatedPaths.hasNext()) {
result.add(activatedPaths.next());
}
return result;
}
ReplicationOptions Class
Encapsulates optional configuration parameters for replication requests.
Official Documentation: ReplicationOptions JavaDoc
Key Methods:
setSynchronous(boolean)
Description: Controls whether replication executes synchronously (blocking) or asynchronously (default).
Parameters:
synchronous-truefor synchronous,falsefor asynchronous (default)
Example:
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true); // Wait for replication to complete
Use cases:
- Synchronous: When you need confirmation before proceeding (e.g., before redirecting user)
- Asynchronous: Better performance for bulk operations
Thread-Blocking Implications:
When setSynchronous(true) is used, the calling thread blocks until replication completes across all target agents. This has important implications:
- UI Performance: In servlets or sling models rendering pages, synchronous replication blocks the HTTP request thread. For large content or slow networks, this can cause noticeable page load delays or request timeouts.
- Thread Pool Exhaustion: High-traffic scenarios with synchronous replication can exhaust the servlet container's request thread pool, causing cascading failures.
- Recommended Pattern: Use asynchronous replication (
false, the default) for user-facing operations. Reserve synchronous mode for background jobs, workflow steps, or cases where immediate confirmation is critical for correctness (e.g., transactional workflows).
Performance Comparison:
- Asynchronous: Request returns immediately after queueing (~10-50ms)
- Synchronous: Request waits for full replication cycle (500ms-5s typical, longer for large assets or network delays)
setFilter(AgentFilter)
Description: Sets the filter for selecting specific agents for replication.
Parameters:
filter-AgentFilterimplementation
Example:
import com.day.cq.replication.AgentFilter;
import com.day.cq.replication.Agent;
ReplicationOptions opts = new ReplicationOptions();
// Filter to specific agent
opts.setFilter(new AgentFilter() {
public boolean isIncluded(Agent agent) {
return agent.getId().equals("publish_instance_1");
}
});
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath, opts);
Use cases:
- Target specific publish instance
- Exclude certain agents
- Route content to specific environments
setSuppressVersions(boolean)
Description: Controls whether to create versions during replication.
Parameters:
suppress-trueto skip version creation,falseotherwise
Example:
ReplicationOptions opts = new ReplicationOptions();
opts.setSuppressVersions(true); // Don't create versions (performance)
setSuppressStatusUpdate(boolean)
Description: Controls whether to update replication status.
Parameters:
suppress-trueto skip status update,falseotherwise
Example:
ReplicationOptions opts = new ReplicationOptions();
opts.setSuppressStatusUpdate(true); // Don't update status metadata
setRevision(String)
Description: Sets the specific revision to replicate.
Parameters:
revision- Revision identifier
Example:
ReplicationOptions opts = new ReplicationOptions();
opts.setRevision("1.0");
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath, opts);
ReplicationStatus Interface
Provides status information about replicated content.
Official Documentation: ReplicationStatus JavaDoc
Key Methods:
// Check if content is activated
boolean isActivated();
// Get last published timestamp
Calendar getLastPublished();
// Get user who last published
String getLastPublishedBy();
// Get last replication action
String getLastReplicationAction();
// Get last replicated revision
String getLastReplicatedRevision();
Example:
import com.day.cq.replication.ReplicationStatus;
import org.apache.sling.api.resource.ResourceResolver;
import javax.jcr.Session;
import java.util.HashMap;
import java.util.Map;
public Map<String, Object> getReplicationMetadata(ResourceResolver resolver, String path) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationStatus status = replicator.getReplicationStatus(session, path);
Map<String, Object> metadata = new HashMap<>();
if (status != null) {
metadata.put("activated", status.isActivated());
metadata.put("lastPublished", status.getLastPublished());
metadata.put("lastPublishedBy", status.getLastPublishedBy());
metadata.put("lastAction", status.getLastReplicationAction());
}
return metadata;
}
Complete Implementation Examples
Example 1: OSGi Service with Replication
package com.mycompany.aem.core.services.impl;
import com.day.cq.replication.Replicator;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.ReplicationOptions;
import org.apache.sling.api.resource.ResourceResolver;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.jcr.Session;
@Component(service = ContentPublisher.class, immediate = true)
public class ContentPublisherImpl implements ContentPublisher {
private static final Logger LOG = LoggerFactory.getLogger(ContentPublisherImpl.class);
@Reference
private Replicator replicator;
@Override
public boolean publishPage(ResourceResolver resolver, String pagePath) {
try {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
// Create options for synchronous replication
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true);
opts.setSuppressVersions(false); // Keep version history
// Activate the page
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath, opts);
LOG.info("Successfully activated page: {}", pagePath);
return true;
} catch (ReplicationException e) {
LOG.error("Failed to activate page: {}", pagePath, e);
return false;
}
}
@Override
public boolean unpublishPage(ResourceResolver resolver, String pagePath) {
try {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true);
// Deactivate the page
replicator.replicate(session, ReplicationActionType.DEACTIVATE, pagePath, opts);
LOG.info("Successfully deactivated page: {}", pagePath);
return true;
} catch (ReplicationException e) {
LOG.error("Failed to deactivate page: {}", pagePath, e);
return false;
}
}
}
Example 2: Servlet with Replication
package com.mycompany.aem.core.servlets;
import com.day.cq.replication.Replicator;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import javax.jcr.Session;
import javax.servlet.Servlet;
import java.io.IOException;
@Component(
service = Servlet.class,
property = {
"sling.servlet.methods=POST",
"sling.servlet.paths=/bin/myapp/publish"
}
)
public class PublishServlet extends SlingAllMethodsServlet {
@Reference
private Replicator replicator;
@Override
protected void doPost(SlingHttpServletRequest request,
SlingHttpServletResponse response) throws IOException {
String path = request.getParameter("path");
String action = request.getParameter("action"); // activate or deactivate
if (path == null || action == null) {
response.setStatus(400);
response.getWriter().write("{\"error\": \"Missing parameters\"}");
return;
}
// Validate path to prevent path traversal
if (!path.startsWith("/content/")) {
response.setStatus(400);
response.getWriter().write("{\"error\": \"Invalid path\"}");
return;
}
try {
Session session = request.getResourceResolver().adaptTo(Session.class);
if (session == null) {
response.setStatus(500);
response.getWriter().write("{\"error\": \"Unable to obtain session\"}");
return;
}
ReplicationActionType type = "activate".equals(action)
? ReplicationActionType.ACTIVATE
: ReplicationActionType.DEACTIVATE;
replicator.replicate(session, type, path);
response.setContentType("application/json");
response.getWriter().write("{\"success\": true, \"path\": \"" + path + "\"}");
} catch (ReplicationException e) {
response.setStatus(500);
response.getWriter().write("{\"error\": \"" + e.getMessage() + "\"}");
}
}
}
Example 3: Workflow Process Step with Replication
package com.mycompany.aem.core.workflows;
import com.adobe.granite.workflow.WorkflowException;
import com.adobe.granite.workflow.WorkflowSession;
import com.adobe.granite.workflow.exec.WorkItem;
import com.adobe.granite.workflow.exec.WorkflowProcess;
import com.adobe.granite.workflow.metadata.MetaDataMap;
import com.day.cq.replication.Replicator;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.ReplicationOptions;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.jcr.Session;
@Component(
service = WorkflowProcess.class,
property = {
"process.label=Custom Replication Process"
}
)
public class CustomReplicationProcess implements WorkflowProcess {
private static final Logger LOG = LoggerFactory.getLogger(CustomReplicationProcess.class);
@Reference
private Replicator replicator;
@Override
public void execute(WorkItem workItem, WorkflowSession workflowSession,
MetaDataMap metaDataMap) throws WorkflowException {
String payloadPath = workItem.getWorkflowData().getPayload().toString();
Session session = workflowSession.adaptTo(Session.class);
try {
// Custom replication logic
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true);
// Get config from process arguments
String processArgs = metaDataMap.get("PROCESS_ARGS", "");
if ("activate".equals(processArgs)) {
replicator.replicate(session, ReplicationActionType.ACTIVATE, payloadPath, opts);
LOG.info("Workflow activated: {}", payloadPath);
}
} catch (ReplicationException e) {
LOG.error("Replication failed in workflow", e);
throw new WorkflowException("Replication failed", e);
}
}
}
Example 4: Bulk Replication with AgentFilter
import com.day.cq.replication.Agent;
import com.day.cq.replication.AgentFilter;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationException;
import com.day.cq.replication.ReplicationOptions;
import org.apache.sling.api.resource.ResourceResolver;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.jcr.Session;
import java.util.List;
public void bulkActivateToSpecificAgent(ResourceResolver resolver,
List<String> paths,
String targetAgentId)
throws ReplicationException {
// Validate parameters
if (paths == null || paths.isEmpty()) {
throw new IllegalArgumentException("Path list cannot be null or empty");
}
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
// Configure options with agent filter
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(false); // Async for performance
opts.setFilter(new AgentFilter() {
@Override
public boolean isIncluded(Agent agent) {
return agent.getId().equals(targetAgentId);
}
});
// Convert List to array
String[] pathArray = paths.toArray(new String[0]);
// Replicate all paths to specific agent
replicator.replicate(session, ReplicationActionType.ACTIVATE, pathArray, opts);
LOG.info("Bulk activated {} paths to agent: {}", paths.size(), targetAgentId);
}
Additional Public APIs
Beyond the core Replicator interface, AEM 6.5 LTS provides additional public APIs for advanced replication management. These are all documented in the official package summary.
AgentManager Interface
Manages replication agents programmatically.
Official Documentation: AgentManager JavaDoc
Key Method:
Map<String, Agent> getAgents()
Returns a map of all available agents (agent ID → Agent instance).
Example:
import com.day.cq.replication.AgentManager;
import com.day.cq.replication.Agent;
import org.osgi.service.component.annotations.Reference;
@Reference
private AgentManager agentManager;
public void listAllAgents() {
Map<String, Agent> agents = agentManager.getAgents();
for (Map.Entry<String, Agent> entry : agents.entrySet()) {
String agentId = entry.getKey();
Agent agent = entry.getValue();
LOG.info("Agent ID: {}", agentId);
LOG.info(" Enabled: {}", agent.isEnabled());
LOG.info(" Transport URI: {}", agent.getConfiguration().getTransportURI());
LOG.info(" Serialization Type: {}", agent.getConfiguration().getSerializationType());
}
}
public Agent getAgentById(String agentId) {
Map<String, Agent> agents = agentManager.getAgents();
return agents.get(agentId);
}
public boolean isAgentEnabled(String agentId) {
Agent agent = agentManager.getAgents().get(agentId);
return agent != null && agent.isEnabled();
}
ReplicationQueue Interface
Manages replication queue operations programmatically.
Official Documentation: ReplicationQueue JavaDoc
Key Methods:
// Get queue name
String getName()
// Get all queue entries
List<ReplicationQueue.Entry> entries()
// Get entries for specific path
List<ReplicationQueue.Entry> entries(String path)
// Get specific entry
ReplicationQueue.Entry getEntry(String path, Calendar after)
// Clear entire queue
void clear()
// Clear specific entries by ID
void clear(Set<String> ids)
// Get queue status
ReplicationQueue.Status getStatus()
// Check if paused
boolean isPaused()
// Pause/resume queue
void setPaused(boolean paused)
// Force retry on blocked entry
void forceRetry()
Example:
import com.day.cq.replication.Agent;
import com.day.cq.replication.ReplicationQueue;
import com.day.cq.replication.AgentManager;
@Reference
private AgentManager agentManager;
public void monitorQueue(String agentId) {
Agent agent = agentManager.getAgents().get(agentId);
if (agent == null) {
LOG.error("Agent not found: {}", agentId);
return;
}
ReplicationQueue queue = agent.getQueue();
// Get queue status
ReplicationQueue.Status status = queue.getStatus();
LOG.info("Queue: {}", queue.getName());
LOG.info("Status: {}", status);
LOG.info("Is Paused: {}", queue.isPaused());
// List all entries
List<ReplicationQueue.Entry> entries = queue.entries();
LOG.info("Queue size: {}", entries.size());
for (ReplicationQueue.Entry entry : entries) {
LOG.info(" Path: {}", entry.getPath());
LOG.info(" Time: {}", entry.getTime());
LOG.info(" ID: {}", entry.getId());
}
}
public void clearQueueForPath(String agentId, String path) {
Agent agent = agentManager.getAgents().get(agentId);
if (agent == null) return;
ReplicationQueue queue = agent.getQueue();
// Get entries for specific path
List<ReplicationQueue.Entry> entries = queue.entries(path);
if (entries.isEmpty()) {
LOG.info("No queue entries for path: {}", path);
return;
}
// Collect entry IDs
Set<String> ids = new HashSet<>();
for (ReplicationQueue.Entry entry : entries) {
ids.add(entry.getId());
}
// Clear specific entries
queue.clear(ids);
LOG.info("Cleared {} entries for path: {}", ids.size(), path);
}
public void pauseQueue(String agentId) {
Agent agent = agentManager.getAgents().get(agentId);
if (agent != null) {
ReplicationQueue queue = agent.getQueue();
queue.setPaused(true);
LOG.info("Paused queue: {}", queue.getName());
}
}
public void forceRetryBlockedQueue(String agentId) {
Agent agent = agentManager.getAgents().get(agentId);
if (agent != null) {
ReplicationQueue queue = agent.getQueue();
queue.forceRetry();
LOG.info("Forced retry on queue: {}", queue.getName());
}
}
ReplicationListener Interface
Listens for replication events in real-time.
Official Documentation: ReplicationListener JavaDoc
Methods:
// Called before replication starts
void onStart(Agent agent, ReplicationAction action)
// Called when log message written
void onMessage(ReplicationLog.Level level, String message)
// Called when replication completes
void onEnd(Agent agent, ReplicationAction action, ReplicationResult result)
// Called on replication error
void onError(Agent agent, ReplicationAction action, Exception exception)
Example:
import com.day.cq.replication.ReplicationListener;
import com.day.cq.replication.Agent;
import com.day.cq.replication.ReplicationAction;
import com.day.cq.replication.ReplicationResult;
import com.day.cq.replication.ReplicationLog;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class CustomReplicationListener implements ReplicationListener {
private static final Logger LOG = LoggerFactory.getLogger(CustomReplicationListener.class);
@Override
public void onStart(Agent agent, ReplicationAction action) {
LOG.info("Replication starting - Agent: {}, Path: {}, Type: {}",
agent.getId(),
action.getPath(),
action.getType());
}
@Override
public void onMessage(ReplicationLog.Level level, String message) {
switch (level) {
case DEBUG:
LOG.debug("Replication: {}", message);
break;
case INFO:
LOG.info("Replication: {}", message);
break;
case WARN:
LOG.warn("Replication: {}", message);
break;
case ERROR:
LOG.error("Replication: {}", message);
break;
}
}
@Override
public void onEnd(Agent agent, ReplicationAction action, ReplicationResult result) {
LOG.info("Replication completed - Agent: {}, Path: {}, Success: {}",
agent.getId(),
action.getPath(),
result.isSuccess());
// Send notification, update metrics, etc.
if (result.isSuccess()) {
// Success handling
notifySuccess(action.getPath());
}
}
@Override
public void onError(Agent agent, ReplicationAction action, Exception exception) {
LOG.error("Replication failed - Agent: {}, Path: {}",
agent.getId(),
action.getPath(),
exception);
// Error handling, alerts, retry logic
alertReplicationFailure(action.getPath(), exception);
}
private void notifySuccess(String path) {
// Custom notification logic
}
private void alertReplicationFailure(String path, Exception e) {
// Custom alert logic
}
}
// Using listener with Replicator
@Reference
private Replicator replicator;
public void replicateWithListener(ResourceResolver resolver, String path)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true);
// Attach custom listener
CustomReplicationListener listener = new CustomReplicationListener();
opts.setListener(listener);
replicator.replicate(session, ReplicationActionType.ACTIVATE, path, opts);
}
AgentFilter Interface
Filters agents for selective replication (detailed earlier).
Official Documentation: AgentFilter JavaDoc
Method:
boolean isIncluded(Agent agent)
Static Fields:
AgentFilter.DEFAULT- Filter for non-specific agentsAgentFilter.OUTBOX_AGENT_FILTER- Filter for distribution operations
Advanced Example:
import com.day.cq.replication.AgentFilter;
import com.day.cq.replication.Agent;
import com.day.cq.replication.ReplicationActionType;
import com.day.cq.replication.ReplicationOptions;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
// Filter by multiple criteria
public class CustomAgentFilter implements AgentFilter {
private final Set<String> allowedAgentIds;
private final String requiredTransportProtocol;
public CustomAgentFilter(Set<String> allowedAgentIds, String protocol) {
this.allowedAgentIds = allowedAgentIds;
this.requiredTransportProtocol = protocol;
}
@Override
public boolean isIncluded(Agent agent) {
// Filter by agent ID
if (!allowedAgentIds.contains(agent.getId())) {
return false;
}
// Filter by enabled status
if (!agent.isEnabled()) {
return false;
}
// Filter by transport protocol
String transportURI = agent.getConfiguration().getTransportURI();
if (transportURI != null && !transportURI.startsWith(requiredTransportProtocol)) {
return false;
}
return true;
}
}
// Usage
Set<String> allowedAgents = new HashSet<>(Arrays.asList("publish1", "publish2"));
AgentFilter filter = new CustomAgentFilter(allowedAgents, "https://");
ReplicationOptions opts = new ReplicationOptions();
opts.setFilter(filter);
replicator.replicate(session, ReplicationActionType.ACTIVATE, path, opts);
Agent Interface
Represents a replication agent.
Official Documentation: Agent JavaDoc
Key Methods:
String getId() // Get agent ID
boolean isEnabled() // Check if enabled
AgentConfig getConfiguration() // Get configuration
ReplicationQueue getQueue() // Get agent's queue
boolean isConnected() // Check connectivity status
Example:
public void inspectAgent(String agentId) {
Agent agent = agentManager.getAgents().get(agentId);
if (agent == null) {
LOG.error("Agent not found: {}", agentId);
return;
}
LOG.info("Agent Details:");
LOG.info(" ID: {}", agent.getId());
LOG.info(" Enabled: {}", agent.isEnabled());
LOG.info(" Connected: {}", agent.isConnected());
AgentConfig config = agent.getConfiguration();
LOG.info(" Transport URI: {}", config.getTransportURI());
LOG.info(" Serialization: {}", config.getSerializationType());
LOG.info(" User: {}", config.getTransportUser());
ReplicationQueue queue = agent.getQueue();
LOG.info(" Queue Name: {}", queue.getName());
LOG.info(" Queue Size: {}", queue.entries().size());
LOG.info(" Queue Status: {}", queue.getStatus());
}
Exception Handling
ReplicationException Hierarchy
try {
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
} catch (ReplicationException e) {
// Base exception for all replication errors
LOG.error("Replication failed", e);
// Common causes:
// - Agent not found
// - Agent disabled or blocked
// - Network connectivity issues
// - Permission denied
// - Target instance unavailable
}
Best Practices for Exception Handling:
public ReplicationResult safeReplicate(ResourceResolver resolver, String path) {
try {
// Check permissions first
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.checkPermission(session, ReplicationActionType.ACTIVATE, path);
// Perform replication
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(true);
replicator.replicate(session, ReplicationActionType.ACTIVATE, path, opts);
return ReplicationResult.success(path);
} catch (ReplicationException e) {
LOG.error("Replication failed for path: {}", path, e);
return ReplicationResult.failure(path, e.getMessage());
}
}
Error Handling Patterns
Choose the appropriate error handling pattern based on your use case.
Pattern 1: Throw Exceptions (Library Code)
When to use:
- Library/utility methods
- Workflow process steps
- OSGi services called by other components
- When caller needs to handle errors differently
Characteristics:
- Propagates errors to caller
- Caller decides error handling strategy
- Most flexible for reuse
Example:
public void activatePage(ResourceResolver resolver, String pagePath)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath);
// Throws ReplicationException on failure
}
Caller handles the exception:
try {
activatePage(resolver, path);
LOG.info("Page activated successfully: {}", path);
} catch (ReplicationException e) {
LOG.error("Activation failed: {}", path, e);
// Caller-specific error handling (retry, alert, etc.)
}
Pattern 2: Return Boolean (Service Layer)
When to use:
- Service layer with internal error logging
- Fire-and-forget operations
- When caller only needs success/failure indicator
- Background/scheduled jobs
Characteristics:
- Logs errors internally
- Returns simple success/failure flag
- Caller doesn't need exception details
Example:
public boolean activatePage(ResourceResolver resolver, String pagePath) {
try {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
LOG.error("Unable to adapt ResourceResolver to Session");
return false;
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath);
LOG.info("Page activated: {}", pagePath);
return true;
} catch (ReplicationException e) {
LOG.error("Replication failed for: {}", pagePath, e);
return false;
}
}
Caller usage:
if (activatePage(resolver, path)) {
// Success path
updateAuditLog(path, "activated");
} else {
// Failure path
updateAuditLog(path, "activation_failed");
}
Pattern 3: HTTP Status Codes (Servlets and REST APIs)
When to use:
- Sling servlets
- REST API endpoints
- Web service integrations
- HTTP-based interfaces
Characteristics:
- Communicates errors via HTTP status codes
- Returns error details in response body
- Standard web semantics
Example:
@Component(
service = Servlet.class,
property = {
"sling.servlet.methods=POST",
"sling.servlet.paths=/bin/myapp/replicate"
}
)
public class ReplicationServlet extends SlingAllMethodsServlet {
@Reference
private Replicator replicator;
@Override
protected void doPost(SlingHttpServletRequest request,
SlingHttpServletResponse response) throws IOException {
String path = request.getParameter("path");
// Validate parameters
if (path == null || path.trim().isEmpty()) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
response.getWriter().write("{\"error\": \"Missing required parameter: path\"}");
return;
}
// Validate path
if (!path.startsWith("/content/")) {
response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
response.getWriter().write("{\"error\": \"Invalid path: must start with /content/\"}");
return;
}
try {
Session session = request.getResourceResolver().adaptTo(Session.class);
if (session == null) {
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
response.getWriter().write("{\"error\": \"Unable to obtain session\"}");
return;
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
response.setStatus(HttpServletResponse.SC_OK);
response.getWriter().write("{\"success\": true, \"path\": \"" + path + "\"}");
} catch (ReplicationException e) {
LOG.error("Replication failed", e);
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
response.getWriter().write("{\"error\": \"" + e.getMessage() + "\"}");
}
}
}
Pattern Comparison
| Pattern | Use Case | Error Details | Caller Control | Example Context |
|---|---|---|---|---|
| Throw Exception | Library code | Full stack trace | High - caller handles | Utility methods, workflow steps |
| Return Boolean | Service layer | Logged internally | Low - success/fail only | Background jobs, scheduled tasks |
| HTTP Status | Web interfaces | JSON error response | Medium - status code + message | REST APIs, servlets |
Choosing the Right Pattern
Use Throw Exception when:
- Building reusable library code
- Caller needs detailed error information
- Different callers need different error handling
- Workflow process steps (WorkflowProcess interface)
Use Return Boolean when:
- Errors are logged and monitored centrally
- Caller only needs success/failure indicator
- Fire-and-forget operations
- Scheduled/background jobs
Use HTTP Status when:
- Building HTTP endpoints (servlets, REST)
- Web service integrations
- Following REST API conventions
- Client needs machine-readable error codes
Anti-Patterns to Avoid
Don't mix patterns:
// BAD: Returning boolean but also throwing exception
public boolean activatePage(String path) throws ReplicationException {
// Confusing - which error handling mechanism?
}
Don't swallow exceptions silently:
// BAD: Silent failure
try {
replicator.replicate(session, type, path);
} catch (ReplicationException e) {
// No logging, no error indication
}
return true; // Always returns true, even on failure
Don't use generic exceptions:
// BAD: Generic exception loses context
public void activate(String path) throws Exception {
// Caller can't distinguish ReplicationException from other errors
}
Do be specific:
// GOOD: Specific exception type
public void activate(String path) throws ReplicationException {
// Caller knows exactly what failed
}
Security Considerations
1. Use Service Users
Never use admin sessions. Create dedicated service users:
Service User Mapping OSGi Configuration:
Create file: ui.config/src/main/content/jcr_root/apps/myapp/osgiconfig/config.author/org.apache.sling.serviceusermapping.impl.ServiceUserMapperImpl.amended-replication.cfg.json
{
"user.mapping": [
"com.mycompany.aem.core:replication-service=replication-service"
]
}
Service User Permissions:
The service user replication-service requires:
- Read permissions on
/content,/conf - Replicate permissions on paths to be activated
- Write permissions on
/var/replication/outbox(for reverse replication)
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.api.resource.ResourceResolver;
@Reference
private ResourceResolverFactory resolverFactory;
public void replicateWithServiceUser(String path) throws ReplicationException {
Map<String, Object> authInfo = new HashMap<>();
authInfo.put(ResourceResolverFactory.SUBSERVICE, "replication-service");
try (ResourceResolver resolver = resolverFactory.getServiceResourceResolver(authInfo)) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
} catch (LoginException e) {
LOG.error("Service user login failed", e);
}
}
2. Permission Checks
Always verify permissions before replication:
public boolean activateIfAllowed(ResourceResolver resolver, String path) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
try {
// Check permission first
replicator.checkPermission(session, ReplicationActionType.ACTIVATE, path);
// Permission granted, proceed
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
return true;
} catch (ReplicationException e) {
LOG.warn("User lacks replication permission for: {}", path);
return false;
}
}
3. Input Validation
Validate paths and parameters:
public void safeActivate(ResourceResolver resolver, String path)
throws IllegalArgumentException, ReplicationException {
// Validate path
if (path == null || path.trim().isEmpty()) {
throw new IllegalArgumentException("Path cannot be null or empty");
}
// Ensure path is under /content
if (!path.startsWith("/content/")) {
throw new IllegalArgumentException("Invalid path: must be under /content");
}
// Check resource exists
Resource resource = resolver.getResource(path);
if (resource == null) {
throw new IllegalArgumentException("Resource not found: " + path);
}
// Validate resource type is replicable
if (!isReplicableResource(resource)) {
throw new IllegalArgumentException(
"Resource is not replicable. Must be cq:Page or dam:Asset, found: "
+ resource.getResourceType());
}
// Safe to replicate
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
}
/**
* Validates if a resource is a replicable content type.
*
* <p>This method checks if the resource represents content that should be replicated
* to publish instances. Only standard AEM content types (pages, assets, experience fragments)
* are considered replicable. System and configuration resources are excluded to prevent
* unintended replication of application code or configuration.</p>
*
* <p><strong>Allowed resource types:</strong></p>
* <ul>
* <li><code>cq:Page</code> - Standard AEM pages and their hierarchies</li>
* <li><code>dam:Asset</code> - Digital Asset Manager (DAM) assets including images, videos, documents</li>
* <li><code>cq:PageContent</code> under <code>/content/experience-fragments/</code> - Experience fragments for content reuse</li>
* </ul>
*
* <p><strong>Excluded paths:</strong> Resources under <code>/apps</code>, <code>/libs</code>,
* <code>/etc/designs</code>, <code>/var</code>, and other system paths are implicitly excluded
* by only accepting the types above.</p>
*
* @param resource the resource to validate (must not be null)
* @return {@code true} if the resource is a standard content type that should be replicated;
* {@code false} if it is a system/configuration resource or unsupported type
* @see <a href="https://experienceleague.adobe.com/en/docs/experience-manager-65-lts/content/implementing/deploying/configuring/replication">AEM Replication Documentation</a>
*/
private boolean isReplicableResource(Resource resource) {
String resourceType = resource.getResourceType();
// Check if it's a page
if (resource.isResourceType("cq:Page")) {
return true;
}
// Check if it's a DAM asset
if (resource.isResourceType("dam:Asset")) {
return true;
}
// Check if it's an experience fragment
if (resource.isResourceType("cq:PageContent") &&
resource.getPath().startsWith("/content/experience-fragments/")) {
return true;
}
// System/config resources should not be replicated
return false;
}
ResourceResolver Lifecycle Management
Caller Responsibility Pattern
Important: When accepting ResourceResolver as a method parameter, the caller is responsible for closing it, not the method.
/**
* Activates a page using the replication API.
*
* @param resolver ResourceResolver (caller must close)
* @param pagePath Path to the page to activate
* @throws ReplicationException if replication fails
*/
public void activatePage(ResourceResolver resolver, String pagePath)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath);
// Do NOT close resolver here - caller owns it
}
Caller usage:
ResourceResolver resolver = null;
try {
resolver = resolverFactory.getServiceResourceResolver(authInfo);
activatePage(resolver, "/content/mysite/en/page");
} catch (LoginException e) {
LOG.error("Service user login failed", e);
} catch (ReplicationException e) {
LOG.error("Replication failed", e);
} finally {
if (resolver != null && resolver.isLive()) {
resolver.close(); // Caller closes
}
}
Try-with-Resources Pattern (Recommended)
When creating the ResourceResolver within your method, use try-with-resources for automatic cleanup:
public void activateWithServiceUser(String pagePath) throws ReplicationException {
Map<String, Object> authInfo = new HashMap<>();
authInfo.put(ResourceResolverFactory.SUBSERVICE, "replication-service");
try (ResourceResolver resolver = resolverFactory.getServiceResourceResolver(authInfo)) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, pagePath);
} catch (LoginException e) {
LOG.error("Service user login failed", e);
throw new ReplicationException("Authentication failed", e);
}
// ResourceResolver auto-closed here
}
Resource Leak Prevention
Common mistake - Resource leak:
// BAD: Resolver never closed
public void activatePage(String path) throws ReplicationException {
ResourceResolver resolver = resolverFactory.getServiceResourceResolver(authInfo);
Session session = resolver.adaptTo(Session.class);
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
// LEAK: resolver not closed
}
Correct pattern:
// GOOD: Try-with-resources ensures cleanup
public void activatePage(String path) throws ReplicationException {
Map<String, Object> authInfo = new HashMap<>();
authInfo.put(ResourceResolverFactory.SUBSERVICE, "replication-service");
try (ResourceResolver resolver = resolverFactory.getServiceResourceResolver(authInfo)) {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
} catch (LoginException e) {
LOG.error("Service user login failed", e);
throw new ReplicationException("Authentication failed", e);
}
}
Manual Close Pattern (Legacy)
If try-with-resources is not an option (pre-Java 7 code):
public void activatePage(String path) throws ReplicationException {
ResourceResolver resolver = null;
try {
Map<String, Object> authInfo = new HashMap<>();
authInfo.put(ResourceResolverFactory.SUBSERVICE, "replication-service");
resolver = resolverFactory.getServiceResourceResolver(authInfo);
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
} catch (LoginException e) {
LOG.error("Service user login failed", e);
throw new ReplicationException("Authentication failed", e);
} finally {
if (resolver != null && resolver.isLive()) {
resolver.close();
}
}
}
Best Practices
- Prefer try-with-resources for all new code
- Document ownership with JavaDoc when accepting ResourceResolver as parameter
- Always check isLive() before closing in finally blocks
- Never close a ResourceResolver you didn't create
- Use service users - never create admin ResourceResolvers
Performance Optimization
1. Use Asynchronous Replication for Bulk Operations
public void bulkActivate(ResourceResolver resolver, List<String> paths)
throws ReplicationException {
Session session = resolver.adaptTo(Session.class);
if (session == null) {
throw new IllegalStateException("Unable to adapt ResourceResolver to Session");
}
ReplicationOptions opts = new ReplicationOptions();
opts.setSynchronous(false); // Non-blocking for better performance
opts.setSuppressVersions(true); // Skip versioning to reduce overhead
String[] pathArray = paths.toArray(new String[0]);
replicator.replicate(session, ReplicationActionType.ACTIVATE, pathArray, opts);
}
2. Batch Multiple Paths
Use array variants instead of looping:
// BAD: Individual calls in loop
for (String path : paths) {
replicator.replicate(session, ReplicationActionType.ACTIVATE, path);
}
// GOOD: Single batch call
String[] pathArray = paths.toArray(new String[0]);
replicator.replicate(session, ReplicationActionType.ACTIVATE, pathArray, opts);
3. Suppress Unnecessary Operations
ReplicationOptions opts = new ReplicationOptions();
opts.setSuppressVersions(true); // Don't create versions
opts.setSuppressStatusUpdate(false); // Keep status tracking
Testing and Validation
Unit Testing with Mocks
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import static org.mockito.ArgumentMatchers.*;
import static org.mockito.Mockito.*;
@ExtendWith(MockitoExtension.class)
*Truncated - read the full file at https://github.com/OCIOStateOfNebraska/stateofnebraska-aem/blob/fb6f50155bb2761f9cf5c227d800d2f9a361c08b/.agents/skills/aem-replication/replication-api/SKILL.md.*